Richard,
I spoke with the tech folks at Wilwood today, and they didn't offer any real explantion for the problem. Their only suggestion was to use fluid with a higher boiling point, but they didn't really think that would solve things. My MC is one of their lower end products, and doesn't have rebuild capability. So, it wasn't really possible to do much internal analysis.
However, I looked closely again today at the pedal assembly and discovered a 1/16" washer on the front bolt between the top of the footwell and the pedal assembly. No washer on the rear bolt. This could very well be causing the piston to move inside the cylinder at an angle - perhaps the same problem Tommy noted in his post. What do you think? In any event, I think I'll add a washer and level things out when I install the new MC. Hope that's the cure, 'cause it's getting a bit pricy to replace MCs every few thousand miles.
Sundance,
I purged the whole system last time I replaced the MC, so I don't think contamination is an issue. Hopefully, the cure is the missing washer. If that fails, I'll get together with you and Doc and we'll fill all reservoirs with Raki and hope for the best (assuming we don't drink it all first).
Kirby,
I got your e-mail, and I'll give you a call in the next day or so. When do you think your car will be on the road? Soon, I hope. Look forward to seeing it. Power to FIAs!!